Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already declare readOnly, idempotent, non-destructive and open-world, so the safety profile is covered. The description still adds genuinely new behavior: a scope-enforcement rule that non-network addresses are refused, which tells the agent a failure mode it would otherwise not anticipate. It stops short of describing error shape or rate limits.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Two sentences, zero filler, and the most decision-relevant clause (what it reads and where it came from) is front-loaded. The scope restriction is placed last as a constraint rather than buried mid-sentence.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a single-parameter read tool with an output schema and full annotation coverage, the description supplies the only things structured fields don't: where the id comes from and that off-network addresses are rejected. Nothing an agent needs to call it correctly is missing.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema coverage is 100% and the schema already explains that the id is the page's https address. The description's "takes the id search returned" adds only the provenance of the value, which is modest but useful additional meaning. Baseline 3 is appropriate when the schema does the specification work.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

Names a specific verb and resource ("Read one page") and enumerates what comes back (title, text, address), which is concrete enough to separate it from the search sibling. The parenthetical "or any page of a site of this network" also scopes the resource precisely.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

"Read one page found with search" and "Takes the id search returned" establish the intended search-then-fetch workflow, and "any other address is refused" states a hard precondition. It does not, however, contrast against list_lit_pages or suggest, so the agent gets usage context but no explicit alternatives.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.